Wireless networking systems have become a prevalent means by which a large number of people worldwide communicate. Wireless communication devices have become smaller and more powerful to meet consumer needs, which include improved portability and convenience. Users have found many uses for wireless communication devices, such as cellular telephones, personal digital assistants (PDAs), notebooks, and the like, and such users demand reliable service and expanded coverage areas.
Wireless communications networks are commonly utilized to communicate information regardless of where a user is located (inside or outside a structure) and whether a user is stationary or moving (e.g., in a vehicle, walking). Generally, wireless communications networks are established through a mobile device communicating with a base station or access point. The access point covers a geographic region or cell and, as the mobile device is operated, it may move in and out of these geographic cells. To achieve uninterrupted communication the mobile device is assigned resources of a cell it has entered and de-assigned resources of a cell it has exited.
A network can also be constructed utilizing solely peer-to-peer communication without utilizing access points. In further embodiments, the network can include both access points (infrastructure mode) and peer-to-peer communication. These types of networks are referred to as ad hoc networks). Ad hoc networks can be self-configuring whereby when a mobile device (or access point) receives communication from another mobile device, the other mobile device is added to the network. As the mobile devices leave the area, they are dynamically removed from the network. Thus, the topography of the network can be constantly changing. In a multihop topology, a transmission is transferred though a number of hops or segments, rather than directly from a sender to a recipient.
Various factors can affect the efficiency and performance of wireless communication in networks, such as an Ultra Wideband (UWB) ad hoc network. For example, the amount of traffic or data communication occurring in a coverage area can reduce data transmission times and produce interference. Therefore, the quality of service (QoS) for communication can be affected by the other communications occurring in the network at substantially the same time. In exclusion-based schemes, such as Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) utilized in wireless LAN (IEEE 802.11) and UWB, the number of simultaneous transmissions and the data throughput may be reduced if there is interference present in the network.
In various system implementations, a channel reservation scheme is provided to allow devices to negotiate access to the channel medium. The efficacy of these reservations, especially for two-party use, depends on the application traffic profile.